Method for expanding pistons



May 7, 1940.

A. WIEBKE METHOD FOR EXPANDING PISTONS Filed Deo. 6. 1937 Pamesa Mey 7, A1940 METHOD FOR XPANDING PISTONS August Wiebke, Los Angeles, Calif., assigner to The Hastings Manufacturing C mm Haitings, Mich., a corporation of Michigan Application December 6, 1937, Serial No. 178,323

` 3 claims. (Ci. zei- 1565) My invention relates to that type of apparatus.

shown and described in my pending application, Serial No. 120,028, and it has among its principal objects to provide an improved mechanism of the character referred to by means of which certain improved. results can be secured and by means of which my new method of expanding pistons can be effectively accomplished.

I have found that byv supporting the wall of l0 a piston upon two spaced supports and applying the hammering actionrthereto between said supports, there is in eifect a bending of the wall portions of the piston outwardly, and that then by resting these bent-out portions directly upon l5 an anvil and applying the hammering action thereto, there is caused a certain expansion of the wall in both directions circumferentially and an equalizing of the bent-out portions and the rest of the circumference of the piston wail.

I have also provided an auxiliary anvil for use with the anvil proper, whereby certain interior struts or web portions of a piston can be reached for the hammering or swaging action.

In order to more fully explain myinvention,

. I have shown the same in illustration on the accompanying sheet of drawings. in which Figure 1 is a vertical sectional view through a machine embodying my invention; y

Figure 2 is a vertical sectional view taken on line 2-2 of Fig. 1;

, Figures 3 and 4 are fragmentary sectional views, similar to Fig. 1, showingmy auxiliary anvils in place for treating an .inner part of a piston; and

Figures 5, 6 and 'l are views of pistons in different stages of treatment.

Referring now in detail to the drawing, my invention as here embodied comprises a body lcasting I0, upon which is adjustably mounted a shelf or supporting member li, held in place by a screw bolt i2, in a slot i3, in thevertical portion il' of said member il, and by means of an adjustment screw i4, operating in an extension i0' of the body I0. Thus said supporting member can be adjusted vertically on said body.

Pivotally mounted between two portions of an angularly positioned part of said supportlngmember, designated i5, is an operating lever` i6, plvoted at I1 and having its lowex` end i6' normally resting upon a spring pressed pin or plungeri, adjustable as tovtension by means of a screw I9, as clearly illustrated in Fig. 1.

A motor 28 is mounted upon said supporting n member Il, and has mounted on its shaft an eccentric cam 2i, which operates on the end of said operating lever I8, as clearly indicated, and p as will be understood from the showing thereof.

The upper end of said operating lever is provided with a hammer 22, of chisel-like form, having its tapering end rounded smooth. Thus it 5 will be seen that the supporting member Il, carries all the operating mechanism thus far described and can be adjusted vertically, according to requirements.

. Mounted upon the top oi. the body I0, is anY 10 anvil 23, -held in place by means of screw bolts 24, 2t, countersunk thereinto, as seen in Fig. 2. At opposite sides of said bodyv and said anvil are v two jaw members, 25, 25, operated together by means of a right andleft hand screw member 15 26, having the operating hand wheel 21, whereby said jaw members can be moved toward and from each other, said jaw members having their upper or operating ends angularly formed to overlie the anvil 23, substantially in the manner indicated. zo

I have provided two round bars, 28, 28, which can be laid upon the top of the body casting, at

opposite sides of the anvil proper, as indicated, said bars extending parallel with said anvil, and being of a diameter greater than the portion of 25 the anvil above the body, as seen, so that when a piston P, is placed longitudinally upon said bars, 28, 28, it 'will be held slightly above the anvil thereunder. y

Referring to Figs. 3 and 4, I have shown an 30 auxiliary anvil 28, of general pyramidal form and having a small upper work end 28','whi1e its base is formed to slide upon and be guided by the anvil proper 23. This auxilia'ryanvl 29 is also adapted to be held-in position by the jaw mem- 35 bers 25, 25, adjusted thereto, as indicated.

In all places the piston is designated P. In Figs. 1 and 2, thepiston P is shown in position,

. supported upon the two roundbars 28, 28, so that the hammer 22 operates on the segmental ange 40 P of said piston, between said supporting bars,

as the piston is turned back and forth by hand circumferentially on said round bars. The operation of the hammer along this internal segmental flange P' operates to bend the side of 5 the piston outwardly, substantially as indicated by the light broken lines in Fig. 5. This is due to the fact that the hammering or swaging is upon that portion of the piston between the round bars and where the body of the piston is above 5o the anvil proper. I

- Now the piston in this bent outward form is placed directly upon the anvil, the round bars 28, 28, having been removed, and the swaging action ofthe hammer is directly upon the ilange u f27' of said piston with the piston resting upon the anvil, whereupon 'the action is to expand the Vflange portions of the piston circumferentially in opposite directions from the place of treatment, which operates to draw in the portions which were bent outwardly as indicated in Fig. 5, tothe positions indicated by the light broken lines in Fig. 6, The result, however, is an enj speed thereof accomplishes this.

In Figs. 3 and 4, pistons having the internal struts or webs P" are shown, with the use of the auxiliary anvil 29, and by means of which these webs or struts P" can be reached and treated to `expand the pistons outwardly in the manner indicated' by the light broken-lines in Fig. 7.

I believe my method of expanding pistons is absolutely new. Through much experimentation with my iirst machine and improvements from time to time, I have found that by holding a piston upon two spaced supports and hammering the wall of the piston outwardly between said supports, there seems to be a bending of the wall portions outwardly between said supports. Then when I remove the supports and apply said bent out portions directly upon the anvil and hammer them so as to cause a certain expansion of said wall in both directions circumferentially, the result is either to expand the wall outwardly circumferentially tothe bent-out position, or to cause a retraction of the bent-out portions slightly, but with the result that the circumference of the piston is expanded as required. Actual tests have proven this method to be successful, and while I have shown means for accomplishing this result, and have described the general operation of the machine shown, I do not -of said wall portions and a drawing in of said bent portions.

2. The method of expanding pistons which includes holding the piston rotatably upon two spaced supports and hammering the wall of said piston outwardly between said supports with short high speed strokes of a hammer, whereby said piston wall is bent outwardly between said supports as it is turned by hand, then resting the bent portion of said piston wall directly upon an anvil and similarly hammering it to expand the metal of said wall circumferentially, whereby said bent portions of said piston wall are drawn inwardly slightly, substantially in the manner indicated.

3. The method of expanding pistons which includes holding the piston rotatably upon two spaced supports and hammering the wall of said piston with rapid short-strokes to bend said piston wall outwardly between said supports while manually turning said piston back and forth on said supports, then holding said bent portions of said piston wall directly upon an anvil and applying said hammer strokes thereto to expand the metal of said wall circumferentially AUGUST WIEBKE. 

